KARST AND HAZARDS LANDS MITIGATION: SOME GUIDELINES FOR GEOLOGICAL AND GEOTECHNICAL INVESTIGATIONS IN ONTARIO KARST TERRAINS

The mandate of the Ontario Geological Survey is to provide citizens and institutions of Ontario with accurate and objective earth science knowledge about Ontario, in order to sustain and support quality of life, economic prosperity, environmental quality, and public health and safety. The OGS does not comment on best practices or recommended approaches for reviewing and approving changes to land-use or development applications in karst terrains.The Ontario ministries of Natural Resources (MNR), Municipal Affairs and Housing (MMAH), and Agriculture and Food and Rural Affairs (OMAFRA) have been reviewing existing policies related to land-use and development throughout southern Ontario and Manitoulin Island to update hazard lands guidelines, nutrient management practices and to develop best practices documents for various forms of development in karst terrains.

The main purpose of this study is to provide a more comprehensive summary of the kinds of geoscience field work and data sets that could be integrated into field-based studies in order to address gaps in the current guidelines framework (e.g., Natural Hazards Technical Guidance documents for use with the current Ontario Provincial Policy Statement). A “best practices” approach to addressing karst hazards should be carried out in a staged manner, one that involves a general geologic- and geomorphologic-data-gathering desktop investigation (Phase 1 study) that would progress to a more detailed field-based study (Phase 2) to quantify and qualify identified karst terrain hazards (i.e., progress from Phase 1- to Phase 2-level site investigation depending upon nature of land use or development project being proposed). An overview of proposed best practices for investigating karst hazards in Ontario and an innovative "toolkit" for investigating karst-influenced groundwater flow zones will be reviewed in this presentation.